Technical Field
The present invention relates to integrated circuit devices, and more particularly to a device and method for fabricating a three-dimensional substrate structure with nanolayers.
Description of the Related Art
With growing concern about low cost clean energy, solar power has again become a focal point for alternatives to fossil fuel energy production. Solar energy, while clean and sustainable, typically relies on expensive technologies for its implementation. These technologies include the incorporation of integrated circuits or integrated circuit technology into the fabrication of solar cells. The expense associated with current solar panels is a strong disincentive from moving in the direction of solar power.
Solar panels employ photovoltaic cells to generate current flow. When a photon hits silicon, the photon may be transmitted through the silicon, reflected off the surface, or absorbed by the silicon if the photon energy is higher than the silicon band gap value. This generates an electron-hole pair and sometimes heat, depending on the band structure.
Nanorods or nanowires may be formed from the top down or from the bottom up. In one method, vertical nanowires are formed from the bottom up using gold nanodots as seeds. The seeds are employed as deposition sites where a high temperature chemical vapor deposition (CVD) process is required to grow the vertical wires from the seeds. This process is difficult to control and undesirable densities and sizes may result. This process is also expensive. In a top down approach, SiO2 or polymer nanospheres are employed as a mask on a substrate. A solution-based coating process is required which is cost-additive and tends to be non-uniform. The process is characterized by relatively low selectivity etching between the mask and the nanowire materials (substrate). This process is also relatively expensive. In both processes, the temperatures are relatively elevated. This has a detrimental effect on the vertical wires formed.